Tortoise Project Takes Off -- Slowly

Restoring The Animals' Habitat At A Preserve Could Take A Decade Of Methodical Work.

January 26, 2004|By Rosalind Jennings, Special to the Sentinel

It's unfortunate, but the large, peaceful land turtle called the gopher tortoise enjoys living on the same high, dry land that people do. Developers tend to bulldoze the land for housing developments.

Development and the way it changes the habitat pose the most serious threat to gopher-tortoise survival.

As environmental program manager for the Lake County Water Authority, Patricia Burgos is working to restore gopher tortoise habitat on authority preserves.

At Flat Island Preserve in southwest Leesburg, a 2,300-acre site accessible to the public, a 10-acre Bahia grass pasture is being restored to make it as tortoise-friendly as possible.

Gopher tortoise shells average 10 inches long. The tortoises are herbivores, although some chew animal bones for the calcium. Their shovel-like forelimbs are adapted for digging.

"I like them so much. They are neat reptiles," Burgos said.

"They get forgotten. They're not aggressive. They're just trying to live their lives. They are so important to the environment because their burrows are home to so many different creatures."

The tortoises are a "keystone species," meaning the tortoises and the tunnel-like burrows they create are pivotal to the existence of other animal species -- about 360 species, in the tortoise's case.

Indigo snakes, gopher frogs and bobcats are just a few creatures that use the burrows, which can be as deep as 10 feet and as long as 40 feet.

Bahia is an invasive grass, so when it dominates, many native plant species can't survive. In decades past, before the water authority acquired the preserve, Flat Island was homesteads and farmland. Settlers planted Bahia to feed cattle.

"Tortoises need to eat a variety of plant life just like we do, and Bahia grass is not their favorite food," Burgos said.

"Bahia grass on an old pasture is not great for gopher tortoises."

Workers have burned the field -- not to kill the Bahia but to "knock it back" so that other plant species can thrive, said water authority resource specialist Dean VanderBleek.

Gopher tortoises need well-drained, sandy soils for burrowing as well as open, sunny areas for nesting and basking.

The tortoises lay three to 15 eggs a year, but predators often destroy them. One nest in 10 years may have hatchlings that survive.

The tortoises take a long time to mature -- about 15 years -- and can live into their 60s. They like to eat herbaceous plants such as gopher apples and saw palmetto berries.

Burgos said longleaf pine and species that complement it, such as the turkey oak and wire grass, should dominate the field once the restoration is well under way.

"We won't be able to get it back to a pristine longleaf pine environment. We will just strive to make it our best, a good mixture of plants for gopher tortoises," Burgos said.

Burgos said the restoration could take five to 10 years or longer. Efforts were started last year. Longleaf pine seedlings were planted a few months ago.

"We're doing the best kind of management we can do on a small budget," Burgos said. "As a land management person, I want to go back in time to pre-settlement, get back to nature and the native species."

She plans to do a base count of the tortoises in the spring and will check on the population yearly. She hopes their numbers will increase.

Burgos said the gopher tortoise population at Flat Island and other preserves faces other potential dangers -- car accidents, maulings by dogs and killings by coyotes or humans.

The tortoises can also pass a respiratory disease to one another. VanderBleek said that for this reason, gopher tortoises from other areas should never be transported into water authority preserves.

Because of dwindling numbers statewide, the tortoises are protected from hunting, harvesting and other practices destructive to the species, and are listed in Florida as a "species of special concern."

Between 700,000 and 1 million gopher tortoises survive in Florida, according to rough estimates.

For information, go to the Gopher Tortoise Council Web site, www.gophertortoise council.org.